Many electronic devices include power supplies that convert high-voltage alternating current (AC) available from wall outlets to low-voltage direct current (DC). Such devices may include information technology equipment (ITE), such as computers, printers, scanners, and so on, as well as audio-video (AV) equipment, such as televisions, stereo equipment, home theatre equipment, and so on. Due to the typical characteristics of the power supplies of such electronic devices, leakage current may flow from primary sides of the power supplies that connect to the high-voltage AC, to secondary sides of the power supplies that provide the low-voltage DC.
If the leakage current of an electronic device is sufficiently high, a user touching the chassis or enclosure of the electronic device may perceive the current. Such user-perceptible touch current may cause the user to feel a tingling sensation, may shock the user, or may have worse deleterious effects. Therefore, most electronic devices are designed so that the maximum amount of leakage current is less than that which a user may perceive. Furthermore, some electronic devices may be designed to connect to the electrical ground afforded by wall outlets to which the leakage current can drain. These devices are known as class I devices, as opposed to class 11 devices that are not designed to connect to the electric ground provided by wall outlets.
Electronic devices are commonly connected to one another. For instance, printers and scanners may be connected to computers, whereas compact disc (CD) players and digital versatile disc (DVD) players are commonly connected to receivers. Leakage current, however, may be additive in nature among connected electronic devices that share a common ground plane. Although the leakage current of a single piece of equipment may be sufficiently diminutive to not cause user-perceptible touch current, such leakage current in combination with the leakage current of other pieces of equipment may result in user-perceptible touch current, causing undesirable effects.
An electronic device of one embodiment of the invention includes one or more wired interconnection points and a blocking mechanism. The one or more wired interconnection points are to interconnect to other electronic devices. The blocking mechanism is situated at the one or more wired interconnect points to reduce leakage current transferred from the other electronic devices over the one or more wired interconnection points.